This invention pertains to ribbon-feeding apparatus of the type for feeding a pliable ribbon wrapped to form supply and take-up rolls typically useful in feeding magnetic recording tape and photographic film. This invention more particularly pertains to a tape transport apparatus of the type in which tension is developed in the tape by driving the take-up roll to take on tape at a rate slightly greater than the rate of unwinding tape from the supply roll.
Heretofore, in tape transport apparatus of the kind described, separate motors have been applied to drive the supply and take-up rolls at different speeds in order to generate tension in the tape span defined between the two rolls. In other arrangements, brakes have been employed on the supply roll so as to cause it to resist unwinding as the tape is wrapped about the take-up roll by means driving the take-up roll. Other means for generating tension in the span of tape defined between supply and take-up rolls are shown in U.S. Pat. No. 3,370,803.
Heretofore, it has been a major objective to obtain a reversible tape transport in which energy is not consumed in the system such as results from using friction in the form of brakes and the like while still maintaining the system in as simple a form and inexpensive a form as possible.
As used herein, the term "tape" shall be deemed to mean any form of elongate, pliable ribbon of a type adapted to be wrapped to form rolls thereof, such as picture film and magnetic recording tape.